Title: Mass Spectrometry based imaging of native biological nanodomains 6. PROJECT SUMMARY/ABSTRACT The application proposes a career development for Dr. Francisco A. Fernandez-Lima, a postdoctoral fellow trained in biological mass spectrometry and instrument & method development. Dr. Fernandez- Lima is committed to a research career in biophysical science to study scientific problems at a molecular and cellular levels by creating new and improving current techniques and methods, that can be further translated to animal based studies, to patient-oriented clinical research, and ultimately lead to improved patient care. The applicant will be mentored by Dr. Emile A. Schweikert in nanometer scale imaging probes for mass spectrometry, co-mentored by Dr. David H. Russell in instrument and method development for biological mass spectrometry, and co-mentored by Dr. Jennifer L. Bizon in behavioral and cellular neuroscience methods and animal models for studies of cognitive impairment diseases. The project, to be conducted at Texas A&M University, proposes the instrumental development of a mass spectrometer coupled to a nanometer imaging probe capable of interrogating native biological surfaces at the single cell and sub-cellular levels (currently not available at the level proposed). The instrument (Specific Aim 1) will employ a cluster beam probe (Au100n+q and Binq+q) at up to 100 qkeV energies for enhanced molecular yield emission (~10 fold increase), and molecular ion localization with sub-100nm lateral resolution using an electron emission microscope. The methodology will be validated using well-defined cellular systems containing known surface markers (e.g., expression of CD4 antigen and hepatocyte growth factor receptor (c-met) from Immune cells (Molt-3) and hepatocytes) to characterize the instrument performance (Specific Aim 2). Fast gas-phase separation (in this case Ion Mobility - Mass Spectrometry, IM-MS) and fragmentation techniques (IM-CID-MS) will be applied to the separation and identification of molecular biomarkers (Specific Aim 3). As a short- term goal, the neuron phenotypic expression, morphology, and/or stability will be correlated with the basal forebrain chemical environment of behaviorally characterized young, middle-aged, and aged F344 rats (Specific Aim 4). Relevance: The project will set the instrumental and methodological basis for single cell and sub-cellular studies of molecular markers associated with cognitive impairment diseases by directly correlating the chemical environment with their biological function using untreated tissue samples.